Hydraulic turbine



NW 7, 1933. c, R. MARTIN HYDRAULIC TURBINE Filed Nov. 20, 1930 3 Sheets-Sheet l Nov. 7, 1933., c. R. MARTIN HYDRAULIC TURBINE Filed Nov. 20, 1930 3 Sheets-Sheet 2 @MM2/Moa Patented Nov.. 7, 1933 nutren STATES HYDRAULIC TURiNE Charles R.

Allis-Chalmers Martin, Wauwatosa, Wis., assignor to Manufacturing Company,

Mil-

waukee, Wis., a corporation of Delaware Application November 20,1930 Serial No. 496,864

e oiaims. (ci. 25e- 117) This invention relates in general to the art of hydraulic power installations and relates more specificallyl to improvements in the construction e' and formation of concrete inlet umes and spiral casings thereof for hydraulic turbines using open and closed iiumes.

it has been the practice iii-hydraulic power installations to provide the floor and ceiling of closed type of inlet flumes with opposed concrete truncated cone supports for the different turbine elements, which project vfrom the floor and from the ceiling to an extent and in a manner to cause 'a non-uniform velocity of now of the waterin the inlet flume 'and to cause the presence of dead water pockets adjacent the base marginal portions of the supporting cones and eddies resulting from said pockets, all of which are undesirable features. 'These objectionable features are eliminated according to this invention and the function of the truncated cone support retained by suppressing the cones. This is accomplished by filling in the side walls of each cone with concrete to provide asuperposed rsuppressed surface or substantially continuous ramp' surface the marginal portions of which extend to the side walls of the inlet flume or double spiral casing and the forward marginal portions thereof intersect the more or less inclined plane surfaces of the floor and ceiling along points farther away from the turbine shaft or in other words nearer the mouth of the spiral casing.

A more specic objectA of the invention, therefore is to provide a double spiral concrete casing inlet flume having opposed, substantially continuous ramp surfaces of concrete in the `floor and ceiling, surrounding the guide casing receiving openings whereby dead Water pockets and eddies ahead of the runner resulting from said pockets are eliminated, and the spiral casing may there- 40 'fore be made with cross-sectional areas such that the water entering the spiral casing will be gradually accelerated to the required now in the guide casing and all sudden increases in velocity eliminated. The substantially continuous water ramps gradually increase the velocity of the water within the rspiral casing and prevent sudden changes of velocity within the casing and oonfine the sudden changes Vof velocity to the points 50 where the water leaves the spiral casing and enters the guide casing.` f

The formation of the ramps in the inlet fiume or spiral casing as contemplated by this invention, further provides additional `masses of concrete for properly supporting the-turbine velements and very materially augments the stability of operation ofthe hydraulic power unit.

The ramp surface further acts as a splitter for the incoming water to vdivide the water flow and tends to eliminate the objectionable pulsating or pendulum swing of the entering water. l

The four primary advantages to be gained in a hydraulic power installation having the improved concrete spiral casing as a portion of its inlet flume, the inlet nume comprisingthe spiral casing itself and the intake 6 or 26, are first, increased efnciency under the same conditions of head and speed; second, increased power; third, smoother operation of the power unit and fourth,

a reduction in the tendency of the water to pit` the various parts of the turbine, such as the discharge ring, theturbine' runner and the guide vane tips. All of theseeif'ects are inter-related and it is contended that the suppression of the supporting cones will eliminate some ofthe contributory causes of loss in power and in efliciency,

of excessive vibration and of pitting of the turbine parts which lie Within the turbine water passages.

Other objects and advantages of the present invention will become apparent from a reading of the specification and of the drawings forming a part thereof on which like or the same numerals areused to designate the same or similar x parts'throughout the various views. Y

Fig. l is a central vertical section through a hydraulic power installation of the vertical shaft turbines, employing one form of spiral inlet casing, constructed according to this invention.

Fig. 2 is a longitudinal horizontal section taken 90 substantially along line II--II of Fig. l, looking in the direction of the arrows.

Fig. 3 is a perspective view of a portion of the spiral inlet casing shown in Fig. 1 and as seen looking in the direction of line II-II of said figure.

Fig. 4 is aY central vertical section through another hydraulic power installation, also of the vertical shaft type, employing a modified-form of spiral inlet casing, constructed according to this invention.

Fig. 5 is a longitudinal horizontal section taken substantially along line V--V of Fig. 4, looking in the direction of the arrows.

Fig. 6 is a perspective view of the spiral inlet 105 casing shown in Fig. 4 with the ceiling thereof tilted from its normal position to more clearlyV disclose the ceiling ramp surface.

Referring to Fig. l reference numeral l is used to designate the concrete ceiling and 2 the con- 110 4 crete floor of. a concrete inlet flume, and spiral inlet casing thereof, of a hydraulic power installation especially applicable for low heads and small hydraulic turbines. 5 is the head water horizontal foundation plate of concrete and resting thereon is the concrete intake 6 of the inlet fiume. A ledge 31 `on intake 6 cooperates lwith the plate 5 to form a passage for directing head water directly into the mouth of the spiral casing. The intake 6 is horizontally divided by a pier 8 extending a substantial distance within the spiral casing of the inlet flume.

19 are provided in the continuations of the parallel side Walls 7 of the spiralcasing, that are.

aligned with cooperating gate slots 19 in the pier 8 and in the head water foundation plate 5 to receive gates for the purpose of excluding water from the spiral casing when repairs or replacements are to be made to the power unit.

The power unit comprises a hydraulic turbine direct-connected by means` of a main: shaft. 13 to a power transforming machine 14, such as an electric dynamo; The dynamo 14 is. mounted directly on aring of concrete formed` in. web ofconcrete. which forms between. itr and. ceiling l a pit' 157 fromv which accessmay be had to the variousY partsof the power unit. The hydraulic'4 turbine is. positioned' directly below the dynamo 14 and: iscarried by a discharge ring` 10 mounted upon the horizontal annular portion of. the old and.l welll known: concrete truncated supporting cones, which portioniis retained in the improved spiral` inlet casing structure. The annular portion is' positioned at a higher elevation thanlthei head water foundation plate 5;v and requires sloping o; the oor to: intersect the reverse spiral curved: wall surfaces substantially in the plane of the said annular support portion or in the plane of the discharge.` ring 10r` directly mounted thereon,.which wall surfaces terminate ina commonv nose 9'. SuchV sloped floors would be intersected by the supporting cones of the prior art power installations of the hydraulic turbine type of which the supporting cone shown in Figurel 4 of the Taylor Patent 1,681,711, patented August 21,` 1928, is a fair representation, substantially as' disclosed by the steep side wall forming the circumferential boundary of said cone. The suppression of the prior art supportin.or cones by filling in with. concrete to provide` a superposed surface on the` sloped iloors of the prior art concrete inlet iiumes or a substantially continuous ramp' surface on said floors according to this invention takes the form as clearly shown in Figs. 2 and 3. The substantially straight or uniform slope elements of the ramp surface provide a multiplicity of paths for the various filaments of water in the spiral casing and result in uniforni increases in the velocities thereof while within the spiral casing and confines sudden velocity changes to the points where the filaments leave the casing and enter the guide casing. Because of the elimination of the dead Water pockets with this ramp construction, eddies resulting therefrom in the water iiowing in the guide casing are eliminated and accordingly pitting of the hydraulic turbine runner 12,V discharge ring- 10 and guide vanes'15 is materially efficient energy conversion realized with the runner 12. The water after having given up most or" its kinetic energy to the runner 12 iiows through the draft tube il from which it discharges into the discharge fiume or tail race 18.

The hydraulic power installation shown in Fig.

ate slotsY ,substantially flat..

and then iiows through the 4 is especially applicable for medium heads and for hydraulic turbines that are larger than those for the installation shown in Fig. 1. The increased span of the intake 26 which corresponds to the intake 6 of the modication shown in Fig. 1 necessitates the use of a plurality 0f supporting piers 28 in order to properly carry the suspended ceiling 21. The intake 26 is provided with pairs of gate slots 19 arranged in series toi receive gates for the same purpose stated in connection with the modification of Fig. 1.

The construction of this modified form of inlet flume and spiral casing forming a part thereof dilers from the one disclosed by Figs. 1-3 inthat both ceiling 21 and iloor 22 are provided with substantially continuous ramp surfaces. Asishown the intake 26 cooperates directlyf with an inclined portion of the head water foundation plate to form a passage for directing Water directly to the mouth of the spiral casingand. thereforefthe degree of suppression in the ramp surfacef rising4 from the slightly inclined plane portion. of the floor 2-2 is correspondingly less thany that'in the ramp,A surface of licor 2, of the modification disclosed by Fig. 1. The degree of suppression in the ramp surface depending from.. the slightly and reversely inclined plane portion. of the-ceiling 21 is morepronounced from thatin the ramp` surface of the` licor 22 but is approximately equal to; that in the ramp surface in. the door 2 of the spiral casing shown in Fig. 1. It will be noted, however, that the extreme rear portions which. terminate in. a point at the nose 29. ofbothv the ceiling and floor ramp surfaces of the.- modiiied spiral casing shown in Fig. 4 are composed of substantially straight line elements that progress irl-inclination from the, nose- 29-as clearly disclosedr by Figs. 5 and 6. whereasy the corresponding portions of the ramp, surface of door 2 of the spiral casing shown in Fig. 1 are With the; latter or modied formation of the opposed ceiling and floor ramp surfaces a spiral casing isV realized in which the cross-sectional ilow areas are such as to effect a grad-ual acceleration of the water entering ythe mouth` of the spi-ral casing to, the velocities. of flow required inthe diierentI peripheral portions of the guide casing and. this modied form of spiral casing isl preferred for medium. heads. Again referring to Figure 4 of the Taylor Patentr 1,681,- 711, which shows a supporting cone hav-ing a` steep side wall and which cone,l as stated before, is fairly reprsentative of the unsuppressed truncated cones of the prior art hydraulic turbine installations, the amount of fill necessary to produce this modified form of spiral inlet casing can be visualized.

The water passing through the spiral casing after having been directed by the guide vanes 15 within the. guide casing impacts against the runner 12, free to rotate Within the discharge ring 10, which absorbs most of its` kinetic energy elbow draft tube 11 from which it discharges into the discharge fiume or tail race 18. Gate slots 30 are provided in the tail race portion of the integral concrete setting of the shown hydraulic power installation and serve to receive the usual tail race stop logs at times required in such installations. 1

While the ramp surface construction or suppressing of the truncated supporting cone idea has been disclosed as-employed in a double spiral inlet concrete casing it is perfectly obvious that the ramp surface construction may readily be applied to and employed in the ordinary type of single spiral concrete casing and in casings having straight end walls.

And although the principle of the invention has been shown as applied and specifically described in connection with vertical shaft hydraulic installations it is perfectly obvious that said principle may equally well be applied to horizontal shaft turbines with beneficial results.

It is also to be understood that in certain cases it may be desirable to have a ceiling ramp surface substantially as shown in Figs. 4, 5 and 6 with a cooperating completely obliterated cone surface or iiat oor surface destroying the identity of the cone support as exemplified in thev floor of the casings of Figs. 1 and 2 of the Iaylor Patent 1,681,711. And that in some cases it may be desirable to use a ramp type of approach as shown in Figs. 1, 2 and 3 in connection with a standard open flume type of setting where the turbine and-its shaft vare completely submerged.

It should be understood that it is not desired to limit the invention to the axact details of construction herein shown and described, for various modifications within the scope of the claims may occur to persons skilled in the art.

It is claimed and desired to secure by Letters Patent:

1. In a hydraulic power installation, a spiral casing having side walls, an end wall, and hav ing a floor and a ceiling provided with alined openings, a fluid intake for said casing, one o said openings serving as a iiuid outlet for said casing, the other of said openings serving in the removal of a part of the installation, said floor having a suppressed cone support terminating in a projecting annular portion surrounding said floor opening, said annular portion being located at a higher elevation than the bottom for said intake and the depth of said spiral casing measured at said annular portion being less than its depth measured at its mouth, said cone support constituting a substantially continuous ramp surface which extends radially outwardly from said annular portion and intersects said side walls and said end wall, said ramp surface being formed to prevent the occurrence of dead water pockets lat the base marginal portions of the cone support.

2. In a hydraulic power installation, a spiral casing having side walls, an end wall, and having a floor and a ceiling providedwith alined openings, a fluid intake forsaid casing, one of said openings serving as a fluid outlet for said casing, the other of said openings serving in the removal of a part of the installation, said floor and said ceiling having each a suppressed cone support terminating in a projecting annular portion surrounding its opening, said floor annular portion being located at a higher eleva tion than the bottom 'for said intake and the depth of said spiral casing measured at said annular portions being less than its depth measured at its mouth, each of said cone supports constituting a substantially continuous ramp sure face extending radially outwardly from its annular portion and intersecting said side walls and said end wall, each of said ramp surfaces co operating to eliminate dead water pockets at the base marginal portions of its cone support.

3. In an inlet flume for hydraulic turbines, a double spiral casing having substantially parallel side walls connected by a double spiral end wall, and having a floor and a ceiling provided with alined openings, one

of said openings serving as a fluid outlet for said casing, the other of said openings serving in the removal of a part of the turbine, said floor having a suppressed cone support terminating in a projecting annular portion surrounding said floor opening, said cone support constituting a substantially continuous ramp surface which extends radially outwardly from said Yannular portion and intersects said end wall and substantially portions of said side walls, said ramp surface cooperating to elimilnate dead water pockets at the base marginal portions of the conersupport.

4. In an inlet flume for hydraulic turbines, a double spiral casing having substantially parallel side walls connected by a double spiral end wall,

and having a floor and a ceiling provided with alined openings, said oor opening serving as a fluid outlet for said casing, said ceiling opening serving in the removal of a part of the turbine, said floor and said ceiling having each a suppressed conesupport terminating in a projecting annular portion surrounding its opening, each of said cone supports constituting a substantially continuous ramp surface extending radially outwardly from its'annular portion and intersecting said end wall and substantial portions of said side walls, each of said ramp surfaces cooperating to eliminate dead water pockets at the base marginal portions of its cone support.

5. In a hydraulic installation, an inlet ume comprising an intake and a spiral casing, said casing having spaced side walls, an end wall and a iioor, said floor being provided with a suppressed cone support, the surface of said cone support being comprised of substantially straight ine elements, those of said elements extending from the top margin of the cone support toward said end end side walls extending substantially to and intersecting said end and side walls at the base margin of the cone support, the remaining line elements of said surface being longer than the shortest of said elements extending to said side walls and extending radially outwardly from the top margin of the cone support to the bottom surface of the spiral casing, and at least some of said remaining line elements extending substantially to the lower portion of the junction between said intake and said casing.

6. In a hydraulic installation, an` inlet ume casing having spaced side walls, an end wall and a floor, said oor being provided with a suppressed cone support, the depth of said spiral casing measured at the top margin of the cone support being less than its depth measured at its mouth, the surface of said cone support being comprised of substantially straight line elements, those of said elements extending from the top margin of the cone support toward said end and side walls extending substantially to and intersecting said end and side walls at the base margin of the cone support, the remaining line elements of saidsurface being longer than the shortest of said elements extending to said side walls and extending radially outwardly from the top margin of the cone support to the bottom surface of the spiral casing, and at least some of said remaining line elements extending sub- 

